Apparatus for emissions control, system, and methods

ABSTRACT

Methods, constructions, and systems for treating engine emissions. An engine includes a crankcase, an air intake, a blow-by vent, and an exhaust port; the crankcase emits blow-by gases through the blow-by vent, and the engine produces an exhaust stream through the exhaust port. The blow-by gases are directed through a blow-by filter to produce filtered gases. The filtered gases are directed back into the air intake of the engine; and the exhaust stream is treated with at least one of a catalytic converter, a flow through filter, and a diesel particulate filter. Total particulate matter (PM) emissions of a turbo-charged diesel engine having an engine crankcase and an exhaust tailpipe are reducible. The total emissions includes particulate matter matter emissions from the engine crankcase added to the particulate matter emissions from the exhaust tailpipe. The method includes filtering blow-by gases and directing filtered blow-by gases back into the engine; and treating the exhaust stream with a catalyst; whereby the total emissions are reduced by greater than 25% when compared to the same engine that does not filter blow-by gases nor treat the exhaust stream. Usable systems include: a blow-by filter in gas-flow communication with a blow-by vent of an engine crankcase; a diesel oxidation catalyst arrangement in gas-flow communication with an exhaust port of an engine crankcase, a diesel particulate filter (active or passive), a flow through filter, and combinations thereof.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of application Ser. No. 10/646,359, filed Aug. 22, 2003, which is incorporated herein by reference application Ser. No. 10/646,359 claims priority under 35 U.S.C. § 119(e) to provisional patent application Ser. No. 60/405,524 filed Aug. 23, 2002, Ser. No. 60/421,889 filed Oct. 28, 2002, and Ser. No. 60/427,510 filed Nov. 18, 2002. The disclosures of Ser. No. 60/405,524 and 60/421,889 and 60/427,510 are incorporated herein by reference.

This application is related to and incorporates the following U.S. Patents herein by reference: U.S. Pat. No. 5,355,973; U.S. Pat. No. 5,426,269; U.S. Pat. No. 5,853,439; U.S. Pat. No. 6,171,355; U.S. Pat. No. 6,355,076; U.S. Pat. No. 6,143,049; U.S. Pat. No. 6,187,073; and U.S. Pat. No. 6,290,739. This application incorporates by reference PCT Publication WO 01/47618 published on Jul. 5, 2001, and PCT Publication WO 00/32295 published on Jun. 8, 2000. This application incorporates by reference commonly assigned U.S. patent application Ser. No. 10/168,906 filed Jun. 20, 2002, published on Mar. 20, 2003 as U.S. 2003-0051455 A1.

TECHNICAL FIELD

This disclosure relates to apparatus and methods for controlling emissions for internal combustion engines, in particular, diesel engines. Preferred arrangements include use of a closed-crankcase filter system, use of a catalytic converter muffler, and combinations thereof.

BACKGROUND

Blow-by gases are created by pressure leakage passed piston rings and by reciprocating motion of pistons. A draft tube from the crankcase emits blow-by in the form of aerosol and coalescence droplets. Chemically, these blow-by emissions are in the form of oil droplets, carbon soot, and debris from wear for fugitive dust. Physically, typically about 50% of the mass is less than one micrometer.

There are various systems that use open crankcase engines. These include heavy duty trucks and buses; light vehicles; off-road mobile vehicles; off-road equipment (e.g. industrial equipment, generators); and marine engines.

Tailpipe emissions include gases, particulate matter, and aerosols. These exhaust streams include hydrocarbons, carbon monoxide, soot, oxides of nitrogen, nitric oxide, nitrogen dioxide, particulate matter, sulfate, and other material.

SUMMARY

Methods, constructions, and systems for treating engine emissions are provided. In general, an engine having a crankcase is provided; the engine has an air intake, a blow-by vent, and an exhaust port; the crankcase emits blow-by gases through the blow-by vent and produces an exhaust stream through the exhaust port. At least a portion of the blow-by gases are directed through a blow-by filter to produce filtered gases. The filtered gases are directed back into the air intake of the engine; and at least a portion of the exhaust stream is treated. The treatment can be using a diesel oxidation catalyst, a flow through filter, a diesel particulate filter, or combinations thereof.

Total emissions of a turbo-charged diesel engine having an engine crankcase and an exhaust tailpipe are reducible using methods and systems described herein. The total emissions includes particulate matter emissions from the engine crankcase added to the particulate matter emissions from the exhaust tailpipe. The method includes running the engine to produce crankcase blow-by gases and an exhaust stream; filtering the blow-by gases and directing filtered blow-by gases back into the engine; and treating the exhaust stream with a diesel oxidation catalyst, a flow through filter, a diesel particulate filter, or combinations thereof; whereby the total emissions are reduced by greater than 25% when compared to the same engine that does not filter the blow-by gases and that does not treat the exhaust stream.

Usable systems include: a diesel engine with an air intake, a crankcase, a blow-by vent, and an exhaust port; a blow-by filter in gas-flow communication with the blow-by vent of the crankcase; and an exhaust treatment arrangement in gas-flow communication with the exhaust port.

In examples of usable systems, there is further including an air filter upstream of the engine; a turbo downstream of the air filter and upstream of the engine; the turbo being in gas-flow communication with the air filter and the air intake of the engine; and the blow-by filter being downstream of the engine and upstream of the turbo; the blow-by filter including a filtered gas port; the filtered gas port being upstream of and in gas flow communication with the turbo.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a vehicle or equipment having an engine with an air intake system and an exhaust system;

FIG. 2 is a perspective view of one embodiment of a filter arrangement useable with the system of FIG. 1, constructed according to principles of this disclosure;

FIG. 3 is an exploded view of the filter arrangement depicted in FIG. 2;

FIG. 4 is a top plan view of the filter arrangement depicted in FIG. 2;

FIG. 5 is a cross-sectional view of the filter arrangement depicted in FIGS. 2-4, the cross-section being taken along the line 5-5 of FIG. 4;

FIG. 6 is a schematic, perspective view of a filter element usable in the filter arrangement of FIGS. 2-5;

FIG. 7 is a top plan view of the filter element of FIG. 6;

FIG. 8 is a cross-sectional view of the filter element of FIGS. 6 and 7, the cross-section being taken along the line 8-8 of FIG. 7;

FIG. 9 is a schematic, side elevational view of one catalytic converter muffler useable according to principles of this disclosure;

FIG. 10 is a side elevational view of another embodiment of a catalytic converter muffler useable according to principles of this disclosure;

FIG. 11 is a side elevational view of another embodiment of a catalytic converter muffler useable according to principles of this disclosure;

FIG. 12 is a side elevational view of another embodiment of a catalytic converter muffler useable according to principles of this disclosure;

FIG. 13 is a cross-sectional view of the catalytic converter muffler shown in FIG. 12, the cross-section being taken along the line 13-13 of FIG. 12;

FIG. 14 is an enlarged, fragmentary view of a portion of the arrangement shown in FIG. 13;

FIG. 15 is a schematic view of a vehicle or equipment having an engine with an air intake system and an exhaust system, similar to FIG. 1, but modified to indicate exhaust treatment;

FIG. 16 is a schematic cross-sectional view of a diesel particulate filter, usable with the system of FIG. 15; and

FIG. 17 is a schematic cross-sectional view of the diesel particulate filter depicted in FIG. 16.

DETAILED DESCRIPTION

Pressure-charged diesel engines often generate “blow-by” gases, i.e., a flow of air-fuel mixture leaking past pistons from the combustion chambers. Such “blow-by gases” generally comprise a gas phase, for example air or combustion off gases, carrying therein: (a) hydrophobic fluid (e.g., oil including fuel aerosol) principally comprising 0.1-5.0 micron droplets (principally, by number); and, (b) carbon contaminant from combustion, typically comprising carbon particles, a majority of which are about 0.1-10 microns in size. Such “blow-by gases” are generally directed outwardly from the engine block, through a blow-by vent.

Exhaust gases are produced in the engine as part of the combustion process. The exhaust gases are directed out of the engine and through a tailpipe. Together, the blow-by gases and tailpipe emissions represent a total emissions volume being released from the engine.

Herein when the term “hydrophobic” fluids is used in reference to the entrained liquid aerosol in gas flow, reference is meant to nonaqueous fluids, especially oils. Generally such materials are immiscible in water. Herein the term “gas” or variants thereof, used in connection with the carrier fluid, refers to air, combustion off gases, and other carrier gases for the aerosol.

The gases may carry substantial amounts of other components. Such components may include, for example, copper, lead, silicone, aluminum, iron, chromium, sodium, molybdenum, tin, and other heavy metals.

Engines operating in such systems as trucks, farm machinery, boats, buses, and other systems generally comprising diesel engines, may have significant gas flows contaminated as described above. For example, flow rates and volumes on the order of 2-50 cubic feet per minute (cfm), typically 5 to 10 cfm, are fairly common.

FIG. 1 illustrates a schematic indicating a typical system 28 in which arrangements to control total emissions would be utilized. The system 28 is depicted in a closed crankcase configuration (CCC). Referring to FIG. 1, block 30 represents a turbocharged diesel engine (also referred to herein as “engine crankcase” or just “crankcase”). Air is taken to the engine 30 through an air filter 32. Air filter or cleaner 32 cleans the air taken in from the atmosphere. A turbo 34 draws the clean air from the air filter 32 and pushes it into engine 30. While in engine 30, the air undergoes compression and combustion by engaging with pistons and fuel. During the combustion process, the engine 30 gives off blow-by gases through a vent 31 (also referred to herein as a crankcase emissions area or a breather port). A blow-by filter arrangement 36 is in gas flow communication with the vent 31 and cleans the blow-by gases to produce filtered gases. The air (filtered gases from the blow-by filter arrangement 36) is directed through a pressure regulator 40, which is integrated with the filter arrangement 36. From there, the air is again pulled through by the turbo 34 and into the engine 30. Regulator valve or pressure valve 40 regulates the amount of pressure in the engine crankcase 30. Pressure valve 40 opens more and more, as the pressure in the engine crankcase increases, in order to try to decrease the pressure to an optimal level. The pressure valve 40 closes to a smaller amount when it is desirable to increase the pressure within the engine. Oil recovered from the blow-by filter arrangement 36 is directed to drain to the oil sump at 41.

The filter arrangement 36 for separating a hydrophobic liquid phase from a gaseous stream (sometimes referred to herein as a coalescer/separator arrangement) is provided. This reduces crankcase emissions over systems lacking such a filter. In combination with a catalytic converter muffler, overall emissions (crankcase and tailpipe) are reduced. In operation, a contaminated gas flow is directed into the coalescer/separator arrangement 36. Within the arrangement 36, the fine oil phase or aerosol phase (i.e., hydrophobic phase) coalesces. The arrangement 36 is constructed so that as the hydrophobic phase coalesces into droplets, it will drain as a liquid such that it can readily be collected and removed from the system. With preferred arrangements as described hereinbelow, the coalescer or coalescer/separator, especially with the oil phase in part loaded thereon, operates as a prefilter for carbon contaminant carried in the gas stream. Indeed, in preferred systems, as the oil is drained from the system, it will provide some self-cleaning of the coalescer because the oil will carry therein a portion of the trapped carbon contaminant.

From the engine 30, exhaust gases are directed through an exhaust port 33 downstream to a diesel oxidation catalyst arrangement, embodied herein as a catalytic converter and muffler 43. The catalytic converter and muffler 43 includes a catalyst that allows for the oxidation of hydrocarbons in the gaseous phase, thereby reducing the concentration of hydrocarbons in the exhaust stream. Due to the concentration reduction, a lower amount of hydrocarbons would be adsorbed onto the surface of the carbonaceous particles or soot in the stream. Thus, there is a mass reduction in the tailpipe emissions when the catalytic converter is utilized. The muffler operates to reduce the sound pressure level emanating from the engine. From the catalytic converter and muffler 43, the exhaust gases are emitted from the tailpipe 45.

In FIG. 15, there is a variation of the system 28′ depicted in FIG. 1. The system 28′ of FIG. 15 shows the exhaust gases being treated at 43′, downstream of the engine 30. The treatment 43′ can be the catalytic converter and muffler 43, as shown in FIG. 1, or can include in combination with or alone, other types of exhaust treatment. Other types of exhaust treatment include treating the exhaust by filtering it through a diesel particulate filter. The diesel particulate filter can be either passive or active. These types of exhaust treatments are discussed in further detail in Section J below. The exhaust treatments at 43′ reduces the concentration of hydrocarbons, particulates, or other mass material. There is typically a muffler used, as well, to reduce the sound pressure level eminating from the engine. After this exhaust treatment at 43′, the exhaust gases are emitted from the tailpipe 45.

A. Multi-Stage Oil Aerosol Separator Embodiment, FIGS. 2-8

Referring to FIG. 2, an embodiment of a blow-by filter 36, also referred to herein as a “crankcase gas filter” or “filter arrangement” 36 is depicted at reference numeral 350. The blow-by filter 36 can be embodied as described in, for example: U.S. patent publication US 2003-0051455 incorporated herein by reference; commonly assigned provisional patent application 60/427,510, incorporated herein by reference; U.S. Pat. No. 6,290,739, incorporated herein by reference; U.S. Pat. No. 6,530,969 incorporated herein by reference; U.S. Pat. No. 6,143,049 incorporated herein by reference; and U.S. Pat. Nos. 5,853,439, 6,171,355, 6,355,076, and 6,540,801 each incorporated herein by reference.

The filter arrangement 350 depicted includes a housing 352 holding a filter element 340 and a regulator valve assembly 351. In the one depicted in the drawings, the housing 352 includes: a body subassembly 357; a valve housing subassembly 400; and a fluid port construction 374.

In the embodiment depicted in FIG. 2, the housing 352 includes a service cover 354 removably attachable to housing body 356. The housing body 356, in the embodiment depicted, includes a generally cylindrical wall 358 defining an interior volume 360 (FIG. 3). The wall 358 includes, on an exterior portion 361, engagement or fastener structure 362 (FIG. 3) for receiving the service cover 354. In particular, the fastener structure 362 includes threads 363 and protrusions 364 that act as stops for the service cover 354 engagement. The service cover 354 defines recesses 365 that receive the protrusion 364 and engage the service cover 354 with the protrusions 364 to prevent rotation of the service cover 354 relative to the body 356.

The service cover 354 has a generally cylindrical outer wall 366, which defines the recesses 365. Joining the outer wall 366 is an end wall 368. When the filter arrangement 350 is operably installed on an engine crankcase, such as the one shown in FIG. 1 at 30, the end wall 368 will form a top cover 369.

In FIG. 5, it can be seen that the service cover 354 also includes an inner wall 3070. The inner wall 3070 is circumscribed by the outer wall 366. Between the inner wall 370 and the outer wall 366, there is defined a groove 371. The groove 371 holds a gasket member 372 for forming a seal 373 between the service cover 354 and the body 356.

Secured to and an integral part of the body 356 is first fluid port construction 374. The first fluid port construction 374 includes a base 376 for engagement with surface 377, forming an end wall 378 for body subassembly 357. The base 376 defines an inner channel or bore 380. The inner bore 380 is in fluid communication with an interior volume 417 of the filter arrangement 350 and with fluid channels outside of the filter arrangement 350, to be explained further below. The inner bore 380 forms a first fluid port 382, which, in certain preferred applications, forms both a fluid inlet and a fluid outlet port, to be explained further below. Extending from the base 376, and in fluid communication with the bore 380, is a fluid tube 384 (FIG. 2) defining a channel or bore 385. Also extending from the base 376 and being coaxial therewith is a fluid tube 386. The tube 386 defines a fluid channel or bore 387. In FIG. 2, it can be seen how the tube 384 and tube 386, in this particular embodiment, have axes that are perpendicular relative to each other. As will be explained further below, in preferred embodiments, the bore 385 receives below-by gases from an engine crankcase, while the bore 387 receives coalesced liquid from the filter arrangement 350 to be returned to, for example, an engine sump. In the particular embodiment illustrated, the tube 384 has a tube 388 extending therefrom. The tube 388 defines a fluid channel or bore 389 for connection to appropriate fluid conduits. Extending from the base 376, and forming a part of the bore 380, is a tube section 390. The tube section 390, in the embodiment shown, is a slotted cylindrical wall 392. The wall 392 defines a plurality of slots 393, extending completely from free end 394 to the base 376. The slots 393 allow the tube section 390 to flex radially inwardly to mateably engage with an end portion 395 of a neck 463 of the body subassembly 357. The wall 392 has catches 396 to allow for the engagement with the end portion 395.

In the embodiment illustrated, a gasket member 398 is oriented between the first fluid port construction 374 and the body subassembly 357, between base 376 and surface 377, to form a seal 399 and prevent leakage therebetween. The neck 463 projects axially inwardly from wall 378 of the body subassembly 357. The neck 463 defines the end portion 395 of the body subassembly 357, which engages the catches 396 of the wall 392. The neck 363 defines an aperture 397, which receives the tube section 390.

Secured to the body subassembly 357, and part of the overall body 356, is valve housing subassembly 400. The valve housing subassembly holds the regulator valve assembly 351. The valve housing subassembly 400 includes a valve housing body 402 and a valve housing cover 404. The valve housing body 402 includes an outer wall 406 defining an open interior volume 407 (FIG. 5).

A second fluid port construction 408 (FIGS. 2-4) is in fluid communication with the interior volume 407 (FIG. 5). The second fluid port construction 408 includes a tube 409 extending from the outer wall 406 and defines an inner fluid passage or bore 410. The tube 409 passes through the outer wall 406 and terminates at a valve seat 412 (FIGS. 3 and 5). The valve seat 412 is defined by a tubular wall 413, which is circumscribed by the outer wall 406.

In FIG. 5, it can be seen that the valve seat 412 defines an inner shoulder 414. The shoulder 414 supports a portion of the valve assembly 3051, a biasing mechanism, such as a spring 416. The spring 416 is biased against another part of the valve assembly 351, diaphragm 418. The diaphragm 418 is held by a groove 419 defined between the outer wall 406 and an internal ring 420 circumscribed by the outer wall 406. As such, the diaphragm 418 is operably oriented between the valve housing cover 404 and the valve housing body 402.

The diaphragm 418, in the embodiment illustrated, includes an outer lip 422 that is seated within the groove 419. The diaphragm 418 extends from the groove 419 and extends across the valve housing body 402 to cover and close the interior volume 407. The diaphragm 418, in the embodiment illustrated, includes an axial extending ring 424 that engages and is received within the spring 416.

Between the diaphragm 418 and service cover 404 is an open volume 426. In operation, when the filter arrangement 350 has sufficient pressure therewithin to overcome the compressive force of the spring 416, the diaphragm 418 is elastically deformed to occupy the space in the volume 426.

The valve housing body 402 includes a plurality of threaded bores 428 for accommodating fasteners, such as bolts 429 to allows selective removability and attachment of the valve housing subassembly 400 to the body assembly 357. This permits servicing of the regulator valve construction 351. A plate 430 is provided to ensure a good connection between the body subassembly 357 and the valve housing subassembly 400. In FIG. 3, it can be seen how the body assembly 357 defines surface 433 for interfacing with the valve housing subassembly 400. In particular, the surface 433 engages the plate 430 and also defines therein fastener receiving bores 434.

The cover 404 is removably attachable to the valve housing body 402. As can be seen in FIGS. 2 and 3, the cover 404 defines fastener flanges 432 for receiving the bolts 429. In the exploded view shown in FIG. 3, it can be seen how the filter arrangement 350 includes within the housing 352 a removable and replaceable filter element 440. The filter element 440 includes within it a first stage coalescer filter 441 and a second stage filter media 442. In use, a liquid entrained gas stream is directed through the first stage coalescer filter 441, in which a portion of the liquid phase is coalesced and removed from the gaseous stream by the first stage coalescer filter 441. The liquid that is coalesced within the first stage coalescer filter 441 drains and exits the housing 352 through the first fluid port construction 374. The gas phase is directed through the second stage filter media 442. The second stage 442 removes at least a portion of particulates from the gas stream, and then the cleaned gas stream is directed into the valve housing subassembly 400 and out through the second fluid port construction 408.

In reference now to FIGS. 6-8, the filter element 440 is depicted as a single, unitary construction 444. In preferred embodiments, the filter element 440 is removable and replaceable from the housing 352. As used herein, the term “unitary” means that the first stage filter 441 and the second stage media 442 cannot be separated without destroying a portion of the element 440. In the particular embodiment illustrated, the element 340 includes first and second opposite end caps 446, 447 that are part of the unitary construction 444. When the filter element 440 is handled, for example, during servicing, both the first stage coalescer filter 441 and the second stage media construction 442 are handled together.

The filter element 440, in preferred embodiments, is constructed similarly to filter element embodiments described in publication WO 01/47618, published on Jul. 5, 2001 and incorporated herein by reference.

In general, the second stage media construction 442 includes a tubular construction of media 448 defining an open filter interior volume 449 (FIG. 8). In preferred implementations, the tubular construction of media 448 will be configured to have a generally cylindrical shape, defining a circular cross-section.

In certain preferred embodiments, the tubular construction of media 448 includes pleated media 450. The pleated media 450 defines a plurality of pleats 451 from which gas to be treated flows. The pleated media 450 acts as a polishing filter to remove some of the particulates and debris from the gas stream before exiting the filter arrangement 350.

The pleated media 450 has a first end 452 and an opposite, second end 453. The length of the individual pleats 451 of the pleat media 450 extends between the first end 452 and the second end 453. In the particular embodiment illustrated, the first end cap 446 is secured to the first end 452 of the media 442, while the second end cap 447 is secured to the second end 453. In certain preferred implementations, the pleated media 450 is embedded and molded within the end caps 446, 447.

The filter element 440 depicted includes at least one filter support 468. In the embodiment shown, the support 468 is an outer, perforated liner 469, extending between the first and second end caps 446, 447 and circumscribing the media 448. In other embodiments, there may be an inner liner within the media 448.

In preferred embodiments, the end cap 446 includes a ring 454 of a molded, polymeric material. The ring 454 defines a center aperture 455 that, in the preferred embodiment illustrated, is centered in the ring 454. By “centered”, it is meant that the aperture 455 has a center of symmetry that is the same as the center of symmetry of the ring 454. In other words, the center 455 is preferably not eccentrically disposed within the ring 454.

The ring 454 also includes an inner, annular surface 456. When filter element 440 is operably assembled within housing 352, the inner annular sealing surface 456 functions as a sealing portion 458. In preferred arrangements, the sealing portion 458 includes a stepped construction 459.

In particular, the stepped construction 459 helps with the insertion and formation of a radial seal 460 (FIG. 5) between the end-cap 446 and the sealing surface 457 of the housing 352. In FIG. 8, the stepped construction 459 includes decreasing diameters and results in a construction that helps with the insertion of the filter element 440 in the body 356. Note that, in the embodiment illustrated, the sealing surface 457 is along an outer wall 461 of a neck 463 of the body subassembly 357.

The sealing portion 458 of the end cap 447 is preferably made from a compressible material, such that there is radial compression of the sealing portion 458 against the sealing surface 457, when the element is operably installed in the housing 352. In general, preferred end caps 446 will comprise a soft, polyurethane foam having an as-molded density of typically, less than 22 lbs per cubic foot, for example about 14-22 lbs. per cubic foot.

Still in reference to FIG. 8, there is a frame construction 462 oriented in the center aperture 455 of the ring 454. The frame construction 462 holds, contains, and encapsulates a region of fibrous media 464. In the construction shown, the fibrous media 464 is used as the first stage coalescer filter 441. In certain preferred arrangements, the fibrous media 464 comprises at least one layer, and typically, a plurality of layers 465 of nonwoven, nonpleated, non open-tubular, coalescing media. In the embodiment shown in FIG. 8, there are two layers 466, 467 of fibrous media 464. Certain usable, example materials for the fibrous media 464 are described further below.

Still in reference to FIG. 8, in the frame construction 462 depicted, the frame construction 462 is a multi-piece, in particular, a two-piece construction including a first frame piece 470 and a second frame piece 472. The first frame piece 470 has a wall or an outer annular rim 474. Axially spanning across one end of the rim 474 and integral with it is a support grid 476, preferably in the form of a porous, mesh screen 478. The screen 478 provides structural support to the media 464 and permits gas flow to reach the media 464.

The wall or rim 474 preferably defines a recess 480 for engaging and receiving a mating detent 482. The detent 482 is part of the second frame piece 472, in the particular preferred embodiment illustrated. The detent 482, recess 480 arrangement provides for convenient, quick assembly and permits the first and second frame pieces 470, 472 to be snapped together. Of course, many other embodiments of mechanical engagement between the first and second frame pieces 470, 472 are contemplated.

The second frame piece 472 preferably includes an annular wall 484 surrounding and defining an open volume 486. In the particular embodiment illustrated, the wall 484 has a generally circular cross-section, which may be constant (to form a cylinder) or tapered to form a conical shape. The second frame piece wall 484 includes first and second opposite ends, 487, 488. In the embodiment illustrated, the end 487 generally corresponds to an inlet end. In preferred orientations, the end 487 will also correspond to an outlet end for coalesced liquids.

Second frame piece 472 also preferably includes a support grid 490 spanning the open volume 486 and integral with the wall 484. Preferably, the grid 490 comprises a screen 491. The screen 491 provides structural support to the coalescing media 464 and preferably engages and holds the downstream face 492 of the media 464.

The first and second frame pieces 470, 472 form an interior volume or retaining pocket 493 to hold, entrap, and encapsulate the coalescing media 464. Preferably, the media 464 is mechanically compressed within the pocket 493, such that the grid 476 engages the upstream face 494 and the grid 490 engages the downstream face 492. As described above, the wall 484 includes projection or detent 482 extending or projecting internally into the volume 486 to engage or snap into the recess 480.

The second frame piece 472 also includes mechanical engagement structure to securably attach to a wall 496 of a tube 498. In particular, the second frame piece 472 and the tube 498 also includes mechanical engagement structure, such as a detent/recess engagement 499. In this manner, the second frame piece 472 easily snaps and interlocks with the tube 498.

Preferred frame constructions 462 also include support ring or frame 502. The support frame 502 helps to center the frame construction 462 and hold it evenly within an open filter interior 449. The support frame 502, in the one depicted, in FIG. 5, includes a ring construction 504 having at least an inner ring 506 and an outer ring 508. The inner ring 506 and the outer ring 508 are preferably joined by a plurality of spokes or ribs 509. Between the inner rings 508 and outer ring 509, the ring construction 504 defines a plurality of gas flow passageways 510 (FIG. 7).

The ring construction 504 and the tube 498 are constructed and arranged to permit convenient manufacturing and assembly. In particular, the ring construction 504 and the tube 498 are configured to be secured together, such as by a mechanical engagement such as a detent/recess arrangement 512.

Referring again to FIG. 8, the filter element 440 preferably includes a flow construction arrangement 515 oriented to direct fluid, such as gas, from the first region of media 441 toward the second stage media 442. In general, the flow construction arrangement 515 preferably includes tube 498 formed by impervious, continuous, uninterrupted wall 496 surrounding and defining an open, fluid passage 517. In preferred embodiments, the tube 498 extends from the downstream face 492 of the first stage coalescer filter 441 at least partially in a direction toward the second end cap 447. In preferred embodiments, the tube 498 extends a complete distance between the downstream face 492 and the second end cap 447. In the particular arrangement depicted, the tube 498 forms an aperture 518, preferably a fluid exit aperture 519, at the end 520 of the wall 516 adjacent to the second end cap 447. In this manner, in this particular arrangement, in preferred embodiments, liquid that is coalesced by the first stage coalescer filter 441 is allowed to collect along the interior 521 of the tube 498 and drip by gravity back through the first stage media 441 and through the first flow port 374 (FIG. 5). Alternate drain arrangements are also usable. While in the depicted embodiment, the entire wall 516 includes an imperforate section 522, in other embodiments, only portions of the wall 496 will be imperforate.

In the embodiment of FIG. 8, the flow construction arrangement 515 is depicted as a conical section 523 having a sloped or tapered wall 496. In preferred constructions, the angle of taper on the wall 496 will be adjusted depending upon the overall length of the element 440.

After passing through the first stage coalescer filter 441, the gas flows through the fluid passageway 517, out through exit aperture 518, and then into a gas flow plenum 524. The gas flow plenum 524 is formed between the wall 496 of the tube 498 and the pleated media 450. The taper on the wall 496 causes the gas flow plenum 524 to be angled between a volume 525 adjacent to the second end cap 447 and a volume 526 adjacent to the first end cap 446 and the frame construction 462 that is smaller than volume 525.

The depicted second end cap 447 includes a ring 528 defining a center aperture 530. The end cap 447 supports a sealing arrangement 532 for forming a seal 533 (FIG. 5) with the housing 352. In the embodiment illustrated in FIG. 5, the particular seal 533 depicted is an axial seal 534 formed between the filter element 440 and an inner sealing surface 535 of the cover member 354. In preferred embodiments, the sealing arrangement 532 includes a projection 536 extending or projecting in an axial direction from a generally flat, planar portion 537 of the second end cap 447. In many preferred embodiments, the projection 536 forms a continuous ring 538 (FIG. 7). Preferred constructions include the end cap 447 and the projection 536 being a single, unitary, molded construction. In preferred embodiments, the end cap 447 is made from a polymeric material, preferably, a compressible polymeric material such as polyurethane. In many preferred embodiments, the second end cap 447 is made from the same material as the first end cap 446. The axial seal 534 helps to prevent gas from bypassing the first stage coalescer filter 441 and the second stage construction of filter media 442.

In preferred applications, the filter arrangement 350 will be mounted for use with engine crankcase 30 in a “top-load” orientation. By the term “top-load”, it is meant that the filter arrangement 350 is installed with respect to the engine crankcase 30 in an orientation that permits servicing or access to the filter arrangement 350 from a position over or above the crankcase, when the engine crankcase 30 is in normal, operable orientation. In top-load configurations, the person servicing the filter arrangement 350 is not required to be in a position underneath or below the engine crankcase 30. Instead, the person servicing the filter arrangement 350 is able to access it from the top of the engine crankcase 30. For example, in a vehicle having an engine that is selectively accessible by a moveable hood, the filter arrangement 350 would be accessible merely by raising the hood of the vehicle and then removing the service cover 354 of the housing 352. It should be understood that alternate orientations of the filter arrangement 350 could also be used.

In operation, one typical filter arrangement 350 would work as follows. Blow-by gases 38 from engine crankcase 30 are taken in through the fluid channel 385 defined by the tube 384. The gases pass into the first fluid port construction 374 and through the fluid channel 380. From there, the gases flow through the first stage coalescer media 441. The coalescer media 441 separates liquids, with any entrained solids, from the rest of the gas stream. The liquid flows out of the first stage coalescer media 441 and, in the preferred orientation (in a top-load configuration), drips back through the coalescer media 441 and drains by gravity back through the first fluid port construction 374. The liquid, which is often oil, will typically be drained through the channel 387 and directed to an oil sump 41 for reuse by the crankcase 30.

The gas stream that is not coalesced by the first stage coalescer filter 441 flows through the fluid passage 517 of the flow construction 515 and through the exit aperture 518, around the end 520 of the wall 496 (making about 180° turn), through the gas flow passageway 510 and into the gas flow plenum 524. Some liquid that remains in the gas may coalesce by impingement against the wall 496 of the flow construction 515 and drip by gravity back through the first stage coalescer filter and then exit the filter arrangement 350 through the first fluid port construction 374.

From the gas flow plenum 524, the gas flows through the second stage filter media 442, which removes additional particles and solids from the gas stream. The gas flow is prevented from bypassing the second stage media 442 due to the seals 460, 533. The cleaned gas then flows downstream from the second stage filter media 442 and into the valve housing subassembly 400.

The gas flows into the interior volume 407 and into the valve seat 412. The gas exits the filter arrangement 350 through the second fluid port construction 408 (also referred to herein as a “filtered gas port”), in particular through the fluid bore or channel 410. From there, the gas is pulled by the turbo 34 back into the engine 300. The regulator valve construction 351 regulates the amount of pressure in the engine crankcase 30. As pressure in the engine crankcase 30 increases, the gas within the volume 407 has an increased pressure. This pressure results in a force to move the diaphragm 418 in a direction against the spring 416 and into the volume 426 toward the valve housing cover 404. When the diaphragm 418 is moved in this direction, the channel 410 is opened more to allow more volume of gas to flow therethrough. When the pressure within the engine crankcase 30 decreases, the regulator valve construction 351 adjusts, in that the diaphragm 418 moves away from the cover 404 and this decreases the opening allowed to flow into the channel 410. When the air intake system vacuum increases, the regulator valve construction 351 closes to prevent the crankcase 30 from reaching larger negative pressures.

The filter arrangement 350 is serviced as follows. When the filter arrangement 350 is mounted in a top-load configuration and the engine crankcase is in a normal, operable orientation, the cover 354 is removed from the housing body 356 by accessing the filter arrangement 350 from a position above or over the engine crankcase 30. If a moveable hood protects the engine, the hood is first raised to expose the engine 30, and then the service cover 354 is removed from a position over the crankcase 30.

The cover 354 is removed from the body 356 by rotating the cover 354 relative to the body 356 and releasing the protrusions 364 from the recesses 365. When the cover 354 is removed from the body 356, the seal 533 between the body 356 and the cover 354 is released. The filter element 440 is exposed. The end of the filter element 440 adjacent to the second end cap 447 is grasped, typically by hand, and the filter element 440 is pulled in an axial direction from the interior 360 of the body 356. As the filter element 440 is pulled from the interior 360, the radial seal 460 between the filter element 440 and body 356 is released. This step removes simultaneously both the first stage coalescer filter 441 and the second stage media construction 442. The filter element 440 is removed from the housing 352 from a position above or over the engine crankcase 30, in preferred orientations. This filter element 440 may then be disposed of, such as by incineration.

A second, new, replacement filter element 440 is then provided. The replacement element 440 also includes the first stage coalescer filter 441 and the second stage media construction 442. The replacement element 440 is inserted through the open end 367 of the body 356. Note that the open end 367 is at an opposite end from the opening of the neck 463. The filter element 440 is oriented such that the sealing portion 458 of the first end cap 446 is compressed between and against the first frame member 472 and the sealing surface 457 of the neck 463 to form radial seal 460 therebetween.

Next, the service cover 354 is placed over the opening 367 of the housing body 356. The cover 354 is rotated into operable security with the body 356 until the protrusions 364 are located within the recesses 365. This also creates axial seal 533 between the service cover 354 and the element 440 by compression of the seal projection 536 on the second end cap 447 against the service cover 354.

Filtration System Performance

Long Term Performance Stability

The filter arrangement disclosed herein uses a 2-stage filtration approach to blow-by lube oil aerosol coalescence: An inertial impaction filter followed by a high surface area diffusion filter. This 2-stage approach provides a combination of long life at high separation efficiencies with general performance stability.

The following test summarizes the mass efficiency of the filter arrangement over its intended service life.

Note the relatively constant nature of the mass efficiency. The time weighed average efficiency for this test was 85.6%. All data fell within ±4%. Recent improvements have increased performance levels to that in excess of 90% today.

Short Term Aging

To accurately measure a closed crankcase ventilation filtration system's performance during a short test time, one must condition or “age” the filter so that stable performance is developed. The disclosed filter arrangement achieves this stability in a relatively short time as the first stage adsorbs oil onto its coarse fiber surface. This adsorption actually improves its efficiency until it stabilizes. The second stage also adsorbs the finer oil aerosol and initiates coalescing with the assistance of its oliophobic coating. Its efficiency drops slightly from its brand new condition as it achieves stability. Thus, the initial “aging” of the two stages off-set each other as they reach an equilibrium. This is achieved within 24 hours of exposure to blow-by aerosol. The following test shows data indicating this level of stability in the early life of the disclosed filter arrangement.

Note the constant nature of the mass efficiency, especially after 24 hours. Three standard deviations were within ±2% after the first 24-hour period. Again, improvements have increased performance levels to that in excess of 90% today.

E. The Embodiment of FIGS. 9-14

FIGS. 9-12 illustrate four different embodiments of the catalytic converter and muffler 43 of FIG. 1. These are represented by references numerals 1001, 1002, 1003, and 1004. Each of the catalytic converter mufflers 1001-1004 includes an exhaust inlet 1005 and an exhaust outlet 1006. Exhaust gases from the engine 300 are directed to the catalytic converter mufflers 1001-1004 through the exhaust inlet 1005. Inside of each of the mufflers 1001-1004, the exhaust gases are treated by a catalyst, and the sound pressure level is reduced. The treated gases then flow through the exhaust gas outlet 1006 and through the tailpipe 45 (FIG. 1).

FIG. 13 shows a cross-sectional view of the muffler 1004. The cross-section of muffler 1004 is typical of the insides of each of the other mufflers 1001, 1002, and 1003 in that each of the mufflers 1001, 1002, and 1003 includes a catalytic converter honeycomb structure or monolith and sound pressure reduction structure.

The reference numeral 2001, FIG. 13, generally designates a muffler assembly according to the present invention. The muffler assembly 2001 has defined therein three general regions: an exhaust introduction, distribution and upstream acoustics region 2005; a catalytic converter region 2006; and a downstream acoustical or attenuation region 2007. Each of regions 2005, 2006, and 2007 may be constructed separately, with the overall assembly prepared through utilization of appropriate clamps, segments, etc. However, in preferred applications as shown in FIG. 13, it is foreseen that the segments 2005, 2006, and 2007 will be constructed in an overall unit 2010 having an outer shell 2011 with no segment seams or cross seams therein. By “cross seam” in this context it is meant that the shell 2011 is not segmented into longitudinally aligned segments, rather it comprises one longitudinal unit, typically (but not necessarily) having at least one and possibly more than one longitudinal seam.

Herein a unit 2010 which is constructed with'no cross seams, i.e., as a single longitudinal unit, will be referred to as an “integrated” unit. To a certain extent, it may be viewed as a muffler assembly having a catalytic converter positioned operably therein. A unit constructed in segments aligned coaxially and joined to one another along cross seams will be referred to as a “segmented” arrangement. It will be understood that to a great extent the principles of the present invention may be applied in either “integrated” or “segmented” units or arrangements. It is an advantage of the preferred embodiment of the present invention, however, that it is well adapted for arrangement as an “integrated” unit.

As will be understood from the following descriptions, the muffler assembly 2001 according to the present invention is constructed to operate effectively and efficiently both as an exhaust noise muffler and as a catalytic converter. With respect to operation as an exhaust noise muffler, many of the principles of operation are found in, and can be derived from, certain known muffler constructions. With respect to these principles, attention is directed to U.S. Pat. Nos. 3,672,464; 4,368,799; 4,580,657; 4,632,216; and 4,969,537, the disclosure of each being incorporated herein by reference. With respect to constructing a catalytic converter and a muffler, attention is directed to U.S. Pat. No. 5,355,973, incorporated herein by reference.

Still referring to FIG. 13, muffler assembly 2001 comprises a cylindrical casing or shell 2011 of a selected predetermined length. Annular end caps 2013 and 2014 respectively define an inlet aperture 2017 and an outlet aperture 2018. The shell 2011 is generally cylindrical and defines a central longitudinal axis 2020. An inlet tube 2022 is positioned within inlet aperture 2017. The inlet tube 2022 has a generally cylindrical configuration and is aligned with its central longitudinal axis generally coextensive or coaxial with axis 2020. It is noted that end portion 2024 of inlet tube 2022 is configured in a manner non-cylindrical and described in detail hereinbelow, for advantage.

Outlet tube 2026 is positioned within outlet aperture 2018. Outlet tube 2026 includes a generally cylindrical portion 2027 aligned with a central longitudinal axis thereof extending generally coextensive with or coaxially with longitudinal axis 2020.

In use, the exhaust gases are directed: (1) into assembly 2001 by passage through inlet tube 2022 as directed by arrows 2030; (2) into the internal region or volume 2031 defined by casing or shell 2011; and, (3) outwardly from assembly 2001 by passage outwardly through outlet tube 2026 as indicated by arrows 2033. Within assembly 2001 both sound attenuation (muffling) and emission improvement (catalytic conversion) occurs.

Referring to region 2005, and in particular inlet tube 2022 positioned therein, the inlet tube 2022 is positioned and secured in place by end cap 2013 and internal baffle 2035. Preferably baffle 2035 is constructed so as not to be permeable to the passage of the exhaust gases therethrough or thereacross. Thus, baffle 2035 in cooperation with end cap 2013 and shell 2011 define a closed volume 2037.

For the embodiment shown in FIG. 13, inlet tube 2022 is perforated along its length of extension within assembly 2001, i.e., that portion of the tube 2022 positioned internally of end cap 2013 (that is positioned between end ca 2013 and end cap 2014) is perforated, as indicated by perforations 2038. Certain of the perforations allow gas expansion (and sound travel) into volume 2037, which assists in attenuation of sound to some degree. Regions such as volume 2037 may be generally referred to as “resonating chambers” or “acoustics”, and similar structure positioned upstream of region 2006 and also constructed and arranged for sound attenuation, will be referred to herein as “upstream acoustics.”

The portion 2042 of inlet tube 2022 which projects inwardly of baffle 2035; i.e, which extends over a portion of the volume between baffle 2035 and outlet end cap 2018 operates as a flow distribution construction or element 2044. The flow distribution element 2044 generates distribution of exhaust gas flow within volume 2045, i.e., the enclosed volume of shell 2011 positioned immediately inwardly of baffle 2035, for advantage. Portion 2042 of inlet tube 2022 includes previously defined end portion 2024.

Positioned immediately downstream of inlet tube 2022 is catalytic converter 2050. Catalytic converter 2050 includes a substrate 2051 having catalyst appropriately positioned thereon. The substrate 2051 is gas permeable, i.e., the exhaust gases pass therethrough along the direction of arrow 2053. The catalytic converter 2050 includes sufficient catalyst therein to effect the desired conversion in the exhaust gases as they pass therethrough. Herein this will be referred to as “an effective amount” of catalyst. The substrate 2051 is sized appropriately for this. Greater details concerning the preferred catalytic converter 2050 is provided hereinbelow.

Preferably the flow distribution element 2044 is sized and configured appropriately to substantially evenly distribute exhaust flow against the entire front or upstream surface 2055 of the catalytic converter 2050. In this manner, lifetime of use in the catalytic converter 2050 is enhanced. Also, the more effective and even the distribution, the less likelihood of overload in any given portion of the catalytic converter 50. This will facilitate utilization of a catalytic converter minimal or relatively minimal thickness, which is advantageous. By the term “substantially evenly” in this context it is meant that flow is distributed sufficiently to avoid substantial “dead” or “unused” volume in converter 2050. Generally, as even a distribution as can be readily obtained, within acceptable backpressure limits is preferred.

In general, the catalytic converter 2050 provides for little or no sound attenuation within the muffler. Thus, the space utilized by the catalytic converter is space or volume of little or no beneficial effect with respect to muffler operation. Under such conditions, minimal thickness or flow path catalytic converter will be preferred, so as not to substantially inhibit muffler (attenuation) operation.

It has been determined that there is a preferred positioning of the catalytic converter 2050 relative to the flow distribution element 2044, for advantageous operation. In particular, most preferred operation occurs when the catalytic converter 2050 is not positioned too close to the flow distribution element 2044, but is also not positioned too far therefrom. Discussion of studies with respect to optimizing the position of the catalytic converter 2050 relative to the flow distribution element 2044 are provided hereinbelow, in detail.

For the arrangement shown in FIG. 13, flow distribution element 2044 comprises end 2024 of tube 2022 crimped or folded into a “star” or “four finned” configuration. Such an arrangement has been used in certain types of muffler assemblies before, see for example Wagner et al. '537 referred to above and incorporated herein by reference. In general, the crimping creates closed edges 2056 and facilitates flow distribution. Unlike for conventional muffler arrangements, for the embodiment of FIG. 13 this advantageous distribution is applied in order to achieve relatively even cross-sectional distribution of airflow into and through a catalytic converter 2050, to advantage. Alternative flow distribution arrangements may be utilized in some applications.

The portion 2060 of the muffler assembly 2001 in extension between the downstream surface 2061 of the catalytic converter 2050 and the outlet end cap 2014 is referred to herein as the downstream acoustical or attenuation segment or end 2007 of the assembly 2001. It is not the case that all sound attenuation which occurs within the assembly 2001 occurs within this region. However, the majority of the sound attenuation will occur in this portion of the assembly 2001.

In general, the downstream acoustical segment 2007 comprises structure placed to facilitate sound attenuation or sound control. In typical constructions, resonating chambers or the like will be included therein. One such construction is illustrated in FIG. 13. The particular version illustrated in FIG. 13 utilizes a sonic choke arrangement 2065 therein in association with resonating chambers, to achieve sound attenuation. It will be understood that a variety of alternate arrangements may be utilized.

Referring more specifically to FIG. 13, acoustical or attenuation segment 2007 includes therein a converging or sonic choke arrangement 2065 supported by sealed baffle 2066. In general, the volume 2068 upstream from sealed baffle 2066 will be constructed or tuned for advantageous low frequency sound attenuation. Such tuning will in general concern the precise location of the sealed baffle 2066, i.e., adjustment in the size of volume 2068. Constructions in which a sonic choke assembly similar to that illustrated as 2065 are positioned within a muffler assembly 2001 by a sealed baffle 2066 advantageously, are described in U.S. Pat. Nos. 3,672,464 and 4,969,537 incorporated herein by reference.

In general, sonic coke assembly 2065 comprises a tube member 2075 mounted coaxially with outlet tube 2026 and, together with outlet tube 2026, supported by baffles 2066 and 2077, and outlet end cap 2018. In certain constructions such as that shown in FIG. 13, tube member 2075 may comprise an extension of an overall tube having no cross seam which includes both the tube member 2075 and the outlet tube 2026 as portions thereof. Alternately stated, for the embodiment shown in FIG. 13, the outlet tube 2026 comprises an end portion of tube member 2075. In the alternative, the outlet tube 2026 may comprise a separate extension of material from tube member 2075; the outlet tube and tube member being joined along a cross seam such that they are oriented substantially coaxial with one another.

For the embodiment shown, the tube member 2075 defines a central longitudinal axis positioned generally coextensive and coaxial with axis 2020. In some constructions, a tube member 2075 with a longitudinal axis off-set from alignment with the inlet axis may be used.

Still referring to FIG. 13 tube member 2075 in combination with outlet tube 2026 defines exit flow for exhaust gases passing along the direction of arrow 2053 through catalytic converter 2050. More specifically, such gases pass through an interior 2080 of the tube member 2075 and outwardly through outlet tube 2026, as indicated at arrows 2033.

Between baffles 2066 and 2077, and externally of tube member 2075, a volume 2085 is defined within shell 2011. An extension 2088 of the combination of tube member 2075 and outlet tube 2026 extending through volume 2085 is perforated as shown by perforations 2084, to allow for expansion of gases into volume 2085. Volume 2085 will operate as a resonator or resonating chamber for attenuation of sound, in particular continued attenuation of low frequency and much of the medium frequency attenuation. The size of the volume 2085 may be selected so that it is tuned for preferred sound attenuation including some high frequency attenuation as well.

Similarly, between baffle 2077 and end cap 2014 chamber 2090 is defined, externally of tube member 2075 and outlet tube 2026, and internally of shell 2011. The portion 2091 of outlet tube 2026 extending between baffle 2077 and end cap 2014 is perforated, to allow expansion of gases (and leakage of soundwaves) into volume 2090. The size and configuration of volume 2090 may be tuned for selected medium and high frequency sound attenuation.

Still referring to FIG. 13, tube member 2075 includes a conical end 2092 which converges from point 2093 to neck 2094, i.e., it converges in extension toward the catalytic converter. On the opposite side of neck 2094 from point 2091, the tube member 2075 diverges at flange 2095 to lip 2096; lip 2096 defining a re-entry port for gases passing through assembly 2001. Such a construction is advantageous for preferred muffler operation and sound attenuation. As indicated above, such a construction is referred to herein as a sonic choke. Sonic chokes are described generally in Rowley et al. U.S. Pat. No. 3,672,494, incorporated herein by reference.

In general, a portion of the soundwaves existing in the gaseous medium of volume 2031 are inhibited from passing through the tube member 2075 by increased acoustical impedance encountered at the narrow neck 2094. Such waves are reflected back, which serves to attenuate the sound level.

F. The Construction of the Catalytic Converter

As indicated generally above, a variety of constructions may be utilized for the catalytic converter 2050.

The catalytic converter 2050 comprises a ceramic structure having a honeycomb-like configuration defining a plurality of longitudinal flow channels extending therethrough. Referring to FIG. 14, the ceramic construction is indicated generally at 2100. For mounting within the assembly 2001, the ceramic core 2100 is provided in a circular configuration, i.e. core 2100 defines a cylindrically shaped item. Although alternate configurations are possible, the cylindrical one described and shown is advantageous for positioning within a cylindrical shell 2011.

A ceramic cylinder having a large plurality of longitudinal channels extending therethrough is a somewhat brittle configuration. It is therefore preferably mounted such that it will be dampened from the shocks and vibrations generally associated with a muffler assembly in a diesel powered vehicle. For the arrangement of FIGS. 13 and 14, the ceramic core 2100 is provided with a dampening mantle or wrap 2101 in extension around an outer periphery 2102 thereof. The mantle 2101 should be provided from a flexible, heat resistant material, such as a vermiculite pad. The material Interam® Mat III available from 3M, St. Paul, Minn. 55144 is usable. In general, for the arrangement shown the mantle 2101 would be about 0.12 in. (0.3 cm) to 0.25 in. (0.64 cm) thick.

For the preferred embodiment the mantle 2101 is retained against the core 2100 by retaining means such as a cylindrical casing 2105 of sheet metal. Preferably the casing 2105 is provided not only in extension around the outside of the mantle 2101, but also with a pair of side flanges bent toward the front face 2055 and rear face 2061, respectively, of the core 2100 to contain the mantle 2101. That is, casing 2105 has first and second side lips or rims 2106 and 2107 folded toward opposite sides of the core 2100. Preferably a circular loop of rope or O-shaped gasket 2109 is provided underneath each of the rims 2106 and 2107, to facilitate secure containment of the core 2100 and mantle 2101 within the casing 2105, without damage.

Referring to FIGS. 13 and 14, it will be understood that the preferred catalytic converter 2050 illustrated is a self contained or “canned” unit, positioned with shell 2011. The converter comprises a ceramic core 2100 positioned within a casing 2105, and protected therein by the mantle 2101 and rope rings 2109. The converter 2050 can thus be readily welded or otherwise secured and placed within shell 2011, with good protection of the core 2100 from extreme vibrations within the assembly 2001. In addition, the mantle 2101 and rings 2109 will help protect the converter 2050 from premature deterioration due to flow erosion.

In a typical system, it is foreseen that the ceramic core 2100 will comprise an alumina magnesia silica (crystalline) ceramic, such as cordierite, extruded from a clay, dried and fired to a crystalline construction. Techniques for accomplishing this are known in the ceramic arts. In many, crystalline ceramics are prepared as catalytic converter cores by application of a wash coat thereto and then by dipping the core into a solution of catalyst. In some, the wash coat and catalyst are applied simultaneously. Typical catalysts utilized would be metallic materials, such as noble or precious metal catalysts, including for example platinum, palladium and rhodium. Other materials such as vanadium have also been used in catalytic converters.

In general, for use within a diesel engine muffler assembly, it is foreseen that the core 2100 should be extruded with a cell density of longitudinal passageways of 200 cells/in² to 600 cells/in².

As indicated above, alternate constructions for the catalytic converter may be utilized. One such alternate construction would be to construct the core from a metallic foil substrate, rather than a ceramic.

G. Operations To Reduce Total Emissions

In reference again to FIG. 1, the diesel engine 30 includes a crankcase emissions area or region generally at 31. The engine 30 also has a tailpipe emissions area generally at 46. Together, the emissions from the crankcase emissions area 31 and the tailpipe emissions area 46 constitute, in this context, “total emissions.” The diesel engine 30 can be one of many types of diesel engines. For example, the diesel engine 30 can be: a 2000 Caterpillar 3126 having 300 horsepower; a 1998 Detroit Diesel Series 60 having 450 horsepower; or a 1991 Detroit Diesel Series 60 having 350 horsepower. In general, it is observed that there are significant emissions coming from the crankcase vent 31. These emissions can be anywhere from 10%-50% of the tailpipe emissions. The emissions coming from the crankcase vent can be in the form of an aerosol containing particulate matter, hydrocarbons, and/or wear metals. This aerosol can contribute to deterioration of asphalt, roadways, etc.

It is advantageous to reduce the total emissions of the system 28 containing the diesel engine 300 by treatment in the crankcase emissions area 31 and the tailpipe emissions area 46. In general, emissions from the crankcase of the engine 30, such as blow-by gas, leaves the crankcase through the breather port in the emissions area 31. The crankcase emissions are treated by, first, coalescing the fine oil phase or aerosol phase of the crankcase emissions. As this aerosol is coalesced into droplets, it will drain as a liquid, for example, to the oil sump region 41 of the engine 30. The gas portion that remains after the coalescing step is then filtered for the removal of particulate material, such as soot, dust, wear metals, and/or other particulates. The filtered gas may then be directed back into the turbo 34 of the engine 30.

Exhaust emissions are passed from the engine 30, and before exiting from the emissions area 46 through the tailpipe 45, the exhaust gases are treated. The exhaust gases are treated by exposing them to a diesel oxidation catalyst. The catalyst allows for the oxidation of hydrocarbons in the gaseous phase to reduce the concentration of hydrocarbons in the gas stream. This can result in a lower amount of hydrocarbons being adsorbed onto the surface of the carbonaceous particles or soot in the exhaust stream. Thus, this results in a mass reduction in the tailpipe emissions.

Together, treating the emissions from the crankcase at the crankcase emissions area 31 and treating the exhaust stream results in a reduction of total emissions of the engine 30 over systems that do not treat the crankcase emissions area or the tailpipe emissions area at all. Also, treating both crankcase emissions and tailpipe emissions results in a reduction and over systems that treat the emissions in just one area but not the other (for example, systems that treat only the crankcase emissions but not the tailpipe emissions or systems that treat only the tailpipe emissions but not the crankcase emissions). Fuels usable to advantage include low sulfur diesel (LSD) fuel with 350 ppm sulfur level and an ultra low sulfur diesel (ULSD) fuel with 8 ppm sulfur level. Also usable with the systems described herein are emulsified forms for fuel such as water-diesel fuel emulsions, as described in, for example, US patent publication US 2003/0084658 A1.

H. Experimental

Experimental testing was conducted to compare the emission performance of three different turbocharged heavy-duty diesel engines, equipped with a Donaldson diesel oxidation catalyst (DOC) muffler (Serials 6000 catalyst formulation) as described in FIGS. 9-14, along with a Donaldson Spiracle™ blow-by filter unit as described in FIGS. 2-8, to engine baseline exhaust gaseous emissions and total emissions, which were defined as the sum of exhaust and crankcase blow-by PM (particulate matter) emissions.

The testing included tailpipe and crankcase emission testing using both open crankcase configuration (OCC) and closed crankcase configuration (CCC). The Donaldson Spiracle™ blow-by filter unit was used during the CCC. The OCC baseline testing was a separate measurement and did not affect the engine exhaust. When the engine was configured in an OCC, the crankcase effluent was routed through a sample filter to allow the collection of crankcase particulate. When the engine was configured in a CCC, the crankcase effluent was routed through the blow-by filter of FIGS. 2-8 before being directed into the intake of the engine. In this manner, crankcase emissions were separately measured for the baseline tests without the blow-by filter of FIGS. 2-8 installed and were added to the tailpipe emissions from the baseline tests to determine the total baseline particulate matter (PM) emissions. The total baseline PM emissions are defined as: Tailpipe PM+Crankcase PM.

Two different diesel fuels were used during these emission tests; on-road No. 2 low sulfur diesel (LSD) fuel with 350 ppm sulfur level and a No. 2 ultra low sulfur diesel (ULSD) fuel with 8 ppm sulfur level. The engine operations and exhaust emission measurements complied with EPA's Code of Federal Regulations (CFR 40, Section 86, Subpart N), and the blow-by emission tests complied with Southwest Research Institute's Standard Operating Procedure 07-043, titled “Blow-By Emissions Measurement of Heavy-Duty Diesel Engines”.

Tables 1-4 show the results of tests that:

(i) demonstate the effect of filtering only exhaust gases through a catalytic converter compared to not filtering exhaust gases through a catalytic converter; and

(ii) demonstrate the effect on total emissions (crankcase+tailpipe) of filtering crankcase gases through a blow-by filter of the type described in FIGS. 2-8 above and filtering exhaust gases through a DOC catalytic converter muffler of the type described in FIGS. 9-14.

TABLE 1 Model Year 1991 DDC Series GO, 12.7 L, 350 HP Total PM PM Tailpipe (Tailpipe and Emissions PM % crankcase) Test Fuel Used g/bhp-hr Reduction % Reduction) Average LSD (350 ppm) 0.188 Baseline Tailpipe Average 0.0180 baseline Crankcase DOC Muffler LSD (350 ppm) 0.150 20.2% 27.2% of FIGS. 9-14 and Blow-By ULSD (8 ppm) 0.136 27.7% 34.0% Filter of FIGS. 2-8 Note: PM % Reduction (Relative to LSD - 350 ppm baseline)

TABLE 2 Model Year 1998 DDC Series GO, 12.7 L, 400 HP Total PM PM Tailpipe (Tailpipe and Emissions PM % crankcase) Test Fuel Used g/bhp-hr Reduction % Reduction) Average LSD (350 ppm) 0.080 Baseline Tailpipe Average 0.013 baseline Crankcase DOC Muffler LSD (350 ppm) 0.069 13.4% 25.8% of FIGS. 9-14 and Blow-By ULSD (8 ppm) 0.062 22.5% 33.3% Filter of FIGS. 2-8 Note: PM % Reduction (Relative to LSD - 350 ppm baseline)

TABLE 3 Model Year 2000 CAT 3126, 7.2 L, 300 HP Total PM PM Tailpipe (Tailpipe and Emissions PM % crankcase) Test Fuel Used g/bhp-hr Reduction % Reduction) Average LSD (350 ppm) 0.140 Baseline Tailpipe Average 0.036 baseline Crankcase DOC Muffler LSD (350 ppm) 0.117 16.4% 33.5% of FIGS. 9-14 and Blow-By ULSD (8 ppm) 0.092 34.3% 47.8% Filter of FIGS. 2-8 Note: PM % Reduction (Relative to LSD - 350 ppm baseline)

TABLE 4 Summary Donaldson Technology Systems Performance: PM Reduction % LSD Baseline 1991-1993 Model 1994-2002 Model Technology System Diesel Fuel Year Engines Year Engines DOC Muffler of LSD 27.2 25.8, 33.5 FIGS. 9-14 and Blow-By Filter of ULSD 34.0 33.3, 47.8 FIGS. 2-8

Summary conclusions from Tables 1-3 are:

-   -   When using LSD fuel as compared to LSD baseline for Tailpipe PM         % reduction only, performance of the DOC (Series 6000) muffler         arrangement (as described in FIGS. 9-14) was: 20.2%, 13.4% and         16.4%. This level of performance is below design and retrofit         verification approval (CARB—California Air Resource Board)         requirements of ≧25% PM reduction.     -   When using ULSD fuel as compared to LSD baseline for Tailpipe PM         % reduction only, performance of the DOC (Series 6000) muffler         arrangement of FIGS. 9-14 improved to: 27.7%, 22.5% and 34.3%.         While ULSD fuel improves performance, performance at ≧25% PM         reduction remains engine dependent and does not allow for         reliable improvement over a wide range of engines.     -   When using either LSD or ULSD fuel as compared to LSD baseline,         and using TOTAL PM (tailpipe PM+crankcase PM) measurements, and         using the DOC (Series 6000) muffler arrangement of FIGS. 9-14         and the blow-by filter system of FIGS. 2-8, performance is         improved. With LSD fuel, TOTAL PM reduction is generally 25% or         greater, for example, 25-35%, specifically 27.2%, 25.8% and         33.5%. With ULSD fuel, TOTAL PM reduction is greater than 25%,         for example, 25-50%, specifically 34.0%, 33.3% and 47.8%. These         results are applicable to a broad range of engines including all         highway, heavy-heavy and medium-heavy duty, 4 cycle, non-EGR,         model year 1991-2003, turbocharged or naturally aspirated diesel         engines ranging from 150 to 600 horsepower. Some specific,         usable engines include:

CATERPILLAR Model Year Engine Family Series 1991 MCT0403FZC1 3116 MCT0403FZD2 3116 MCT0403FZE3 3116 MCT0629FZD4 3176 MCT0893FPBX 3406 MCT0893FZD5 3406 1992 NCT0403FZC0 3116 NCT0403FZD1 3116 NCT0403FZE2 3116 NCT0403FZF3 3116 NCT0629FZD3 3176 NCT0638FPCX 3306 NCT0893FPB9 3406 NCT0893FZD4 3406 1993 PCT0403FZC9 3116 PCT0403FZDX 3116 PCT0403FZE0 3116 PCT0629FZD1 3176 PCT0629FZE2 3176 PCT0638FPC8 3306 PCT0893FPB7 3406 PCT0893FZD2 3406 PCT0893FZE3 3406 PCTO403FZF1 3116

NAVISTAR Model Year Engine Family Series 1991 MNV0360EPC7 * MNV0360FPCX * MNV0466EPC4 * MNV0466FPC7 * 1992 NNV0360EPC6 * NNV0360FPC9 * NNV0466EPA1 * NNV0466FPC6 * 1993 PNV0360FPC7 DTA-360 PNV0408FPA2 DT-408 PNV0408FPB3 DT-408 PNV0466EPAX DT-466 PNV0466FPC4 DTA-466 PNV0466FPD5 DTA-466 PNV0466FPE6 DT-466 PNV0466FPF7 DT-466 PNV0530FPA2 * PNV07.3EPA2 *

CUMMINS Model Year Engine Family Series 1991 MCE0359FAA9 B5.9 MCE0359FABX B5.9 MCE0505FAA2 C8.3 MCE0611FZA2 L10 MCE0611FZB3 L10 MCE0611FZD5 L10 MCE0855FZA6 N14 MCE0855FZB7 N14 MCE0855FZC8 N14 MCE0855FZD9 N14 1992 NCE0359FAA8 B5.9 NCE0359FAB9 B5.9 NCE0359FAB9 B5.9 NCE0359FACX C8.3 NCE0505FAA1 C8.3 NCE0505FAB2 C8.3 NCE0611FZA1 L10 NCE0611FZB2 L10 NCE0611FZB2 L10 NCE0611FZD4 L10 NCE0855FZA5 N14 NCE0855FZB6 N14 NCE0855FZC7 N14 NCE0855FZD8 N14 NCE0855FZFX N14 NCE0855FZG0 N14 1993 PCE0359FAA6 B5.9 PCE0359FAB7 B5.9 PCE0359FAC8 B5.9 PCE0359FAD9 B5.9 PCE0505FAAX C8.3 PCE0505FAB0 C8.3 PCE0611FZAX L10 PCE0611FZB0 L10 PCE0661FZA2 M11 PCE0661FZB3 M11 PCE0855FZA3 N14 PCE0855FZB4 N14 PCE0855FZC5 N14 PCE0855FZD6 N14 PCE0855FZF8 N14 PCE0855FZG9 N14 PCE0855FZHX N14 PCE0855FZK4 N14

DDC Model Year Engine Family Series 1991 MDD11.1FZA2 * MDD12.7FZAX * 1992 NDD11.1FZA1 * NDD12.7FZA9 * 1993 PDD08.5FZB7 * PDD08.5FZK7 * PDD11.1FZAX * PDD11.1FZD2 * PDD12.7FZA7 * PDD12.7FZDX *

MACK Model Year Engine Family Series 1991 MMT0728FAF1 E7, EM7 MMT0728FAG2 E7, EM7 MMT0728FAH3 E7, EM7 1992 NMT0728FAA6 E7 NMT0728FAB7 EM7 NMT0728FAC8 EM7 NMT0728FAD9 E7, EM7 NMT0728FAEX E7 NMT0728FAF0 EM7 NMT0728FAG1 E7 NMT0728FAH2 E7 NMT0728FAK7 EM7 NMT0728FAL8 EM7 1993 PMT0728FAC6 EM7 PMT0728FAD7 EM7 PMT0728FAE8 E7 PMT0728FAF9 E7 PMT0728FAGX E7 PMT0728FAH0 EM7 PMT0728FAJ4 EM7 PMT0728FAL6 E7 PMTO728FAB5 E7

FORD Model Year Engine Family Series 1991 MFM07.8FPK8 * 1992 NFM07.8FPK7 * 1993 none *

GENERAL MOTORS Model Year Engine Family Series 1991 none * 1992 NGM06.5EAB5 * 1993 none *

HINO Model Year Engine Family Series 1991 MHM03.8FAA0 * MHM06.5FAA6 * 1992 NHM03.8FAAX * 1993 PHM03.8FAA8 * PHM06.5FAA3 *

ISUZU Model Year Engine Family Series 1991 none * 1992 NSZ0396FAB7 * 1993 PSZ0396FAB5 *

MERCEDES BENZ Model Year Engine Family Series 1991 MMB5.96FAA3 * 1992 NMB5.96FAA2 * NMB12.0FAA4 * 1993 PMB5.96FAA1 * PMB12.0FAA2 *

MITSUBISHI Model Year Engine Family Series 1991 none * 1992 NMM0302FAA0 * NMM0460FAA6 * 1993 PMM0302FAA9 * PMM0460FAA4 *

NISSAN Model Year Engine Family Series 1991 none * 1992 NND0423FAC9 * NND0452FAC9 * 1993 PND0423FAC7 * PND0452FAC7 *

PERKINS Model Year Engine Family Series 1991 MPE0365FAA1 Phaser 180Ti 1992 NPE0365FAA0 Phaser 180Ti 1993 PPE0365FAA9 Phaser 180Ti

RENAULT Model Year Engine Family Series 1991 MRE0335FAA4 * 1992 NRE0335FAA3 * NRE0377FAC0 * NRE0377FABX * 1993 PRE0335FAA0 * PRE0377FAB8 * PRE0377FAC9 *

VOLVO Model Year Engine Family Series 1991 MVT06.7FAA1 * MVT12.0FAA0 * 1992 NVT06.7FAA0 * NVT12.0FAAX * NVT12.0FAB0 * 1993 PVT06.7FAA9 * PVT12.0FAA8 * PVT12.0FAB9 *

MACK Model Year Engine Family Series 1994 RMK728EGDARA E7, EM7 RMK728EJDARA E7, EM7 1995 SMK728EGDARA E7, EM7 SMK728EJDARA E7 1996 TMK728EGDARA E7, EM7 TMK728EJDARA E7 1997 VMK728EGDARA E7, EM7 VMK728EJDARA E7, EM7 VMK728EJDAYW E7, EM7 1998 WMKXH11.9E51 E7 WMKXH11.9E52 E7 WMKXH11.9E53 EM7 1999 XMKXH11.9E54 E7 2000 YMKXH11.9H56 E7, EM7 YMKXH11.9V57 E7, EM7 2001 1MKXH11.9H56 E7, EM7 1MKXH11.9H59 E7 1MKXH11.9V57 E7, EM7 1MKXH11.9V60 E7 1MKXH11.9V61 EM7 2002 2MKXH11.9H59 E7 2MKXH11.9H63 E7 2MKXH11.9V60 E7 2MKXH11.9V61 EM7 2MKXH11.9V65 E7 2MKXH11.9V66 EM7 2MKXH11.9V67 E7

ISUZU Model Year Engine Family Series 1994 none * 1995 none * 1996 none * 1997 none * 1998 WSZXH07.84RA * 1999 XSZXH07.84RA * 2000 YSZXH07.84RA * 2001 1SZXH06.63RK * 2002 2SZXH07.84RA * 2SZXH06.64RA *

MERCEDES BENZ Model Year Engine Family Series 1994 RMB6.0D6DARA * 1995 SMB6.0D6DARA * 1996 none * 1997 none * 1998 WMBXH4.25DJA * 1999 XMBXH6.37DJA XMBXH4.25DJA 2000 YMBXH6.37DJA YMBXH4.25DJA 2001 1MBXH6.37DJC 1MBXH4.25DJA 1MBXH6.37DJA 1MBXH12.0DJA 1MBXH12.8DJA 2002 2MBXH4.25DJA 2MBXH6.37DJA 2MBXH6.37DJC 2MBXH12.0DJA 2MBXH12.8DJA 2MBXH15.9DJB

CATERPILLAR Model Year Engine Family Series 1994 RCP629EZDARA * RCP638EZDARA * RCP893EZDARA * 1995 SCP403DZDARK * SCP442DZDARK 3126 SCP629EZDARK * SCP629EZDARM C-10, 3176 SCP638EZDARA * SCP729EZDARL C-12 SCP893EZDARK * 1996 TCP403DZDARK 3116 TCP442DZDARK 3126 TCP629EZDARK 3176 TCP629EZDARM C-10 TCP638EZDARA 3306 TCP729EZDARL C-12 TCP893EZDARK 3406 1997 VCP403DZDARK 3116 VCP442DZDARK 3126 VCP629EZDARK 3176 VCP629EZDARX C-10 VCP638EZDARA 3306 VCP729EZDARX C-12 VCP893EZDARA 3406 VCP893EZDARX 3406 VCP967EZDARK 3406 1998 WCPXH0442HRK 3126 WCPXH0442HRK 3126 WCPXH0442HSK 3126 WCPXH0442HSK 3126 WCPXH0629ERK C-10 WCPXH0629ERK C-10 WCPXH0729ERK C-12 WCPXH0729ERK C-12 WCPXH0893ERK 3406 WCPXH0893ERK 3406 WCPXH0967ERK 3406 WCPXH0967ERK 3406 1999 XCPXH0442HRK 3126 XCPXH0442HSK 3126 XCPXH0629ERK C10 XCPXH0729ERK C12 XCPXH0893ERK 3406 XCPXH0967ERK 3406 2000 YCPXH0442HRK 3126 YCPXH0629ERK C-10 YCPXH0729ERK C-12 YCPXH0893ERK C-15 YCPXH0967ERK C-16 2001 1CPXH0442HRK 3126 1CPXH0629ERK C-10 1CPXH0729ERK C-12 1CPXH0893ERK C-15 1CPXH0967ERK C-16 2002 2CPXH0442HRK 3126 2CPXH0629ERK C-10 2CPXH0729ERK C-12 2CPXH0893ERK C-15 2CPXH0967ERK C-16

NAVISTAR (INTERNATIONAL) Model Year Engine Family Series 1994 RNV466D6D0TW * RNV466D6DARW DT 466HT, DT 466 RNV466D6DASW DT 466HT, DT 466 1995 SNV444C8DORA * SNV444C8DOSA * SNV466D6DARA DT 466HT, DT 466 SNV466D6DASA DT 466 SNV466D6DATA * SNV466D8DARB DT 466HT, DT 466 SNV466D8DASB DT 466 SNV466D8DATB * SNV530D6DARA * SNV530E6DASA * 1996 TNV444C8DORA * TNV444C8DOSA * TNV466D6DARB DT 466, DT 466HT TNV466D6DATB * TNV466D8DARB DT 466, DT 466HT TNV466D8DATB * TNV530D6DARA * TNV530D8DARA * TNV530E6DASA * TNV530E8DASA * 1997 VNV444C8DARW T444E VNV444C8DASW T444E HT VNV466D6DARA DT 466HT, DT 466 VNV466D8DARW DT 466E, DT 466 HT VNV466D8DASA * VNV530D6DARA 530 MGD VNV530D8DARA 530E VNV530E6DASA 530 HVY VNV530E8DASA 530E 1998 none * 1999 XNVXH0444ANA T 444E XNVXH0444ANB T 444E XNVXH0466ANA DT 466E XNVXH0466ANB DT 466E XNVXH0530ANA 530E XNVXH0530ANB 530E XNVXH07.3ANE 7.3 DIT XNVXH07.3ANF 7.3 DIT XNVXA07.3CNJ 7.3 DIT 2000 YNVXH0444ANA 444 P YNVXH0444ANB T 444E YNVXH0444ANC T 444E YNVXH0466ANA DT 466E, DT 466E HT YNVXH0466ANB DT 466E, DT 466E HT YNVXH0530ANA DT 530E YNVXH0530ANB DT 530E, DT 530E HT YNVXH07.3ANA 7.3 DIT 2001 1NVXH0444ANA 444 P 1NVXH0444ANB T 444E 1NVXH0444ANC T 444E 1NVXH0466ANA DT 466, DT 466 HT 1NVXH0466ANB DT 466, DT 466 HT 1NVXH0466ANB DT 466, DT 466 HT 1NVXH0530ANA DT 530 1NVXH0530ANB DT 530, DT 530 HT 1NVXH07.3ANA 7.3 DIT 1NVXH07.3ANC 7.3 DIT 1NVXH07.3CND 7.3 DIT 2002 2NVXH0444ANA T 444E 2NVXH0444ANB T 444E 2NVXH0444ANC T 444E 2NVXH0466ANA DT 466, DT 466 HT 2NVXH0466ANB DT 466, DT 466 HT 2NVXH0530ANA DT 530 2NVXH0530ANC DT 530 2NVXH0530ANB DT 530, DT 530 HT 2NVXH07.3ANA 7.3 DIT 2NVXH07.3ANC 7.3 DIT 2NVXA07.3CND 7.3 DIT

CUMMINS Model Year Engine Family Series 1994 RCE611EGDARW L10 RCE661EJDARA M11 RCE661EJDARC M11 RCE661EJDARW M11 RCE855EJDARW N14 RCE855EJDASW N14 1995 SCE611EGDARW L10 SCE661EJDARA M11 SCE661EJDARC M11 SCE661EJDARW M11 SCE661EJDASW M11 SCE661EJDATW M11 SCE855EJDARA N14 SCE855EJDARB N14 SCE855EJDARW N14 SCE855EJDASW N14 SCE855EJDATW N14 1996 TCE661EJDARA M11 TCE661EJDARB M11 TCE661EJDARC M11 TCE661EJDARW M11 TCE661EJDASW M11 TCE661EJDATW M11 TCE855EJDARA N14 TCE855EJDARB N14 TCE855EJDARW N14 TCE855EJDASW N14 TCE855EJDATW N14 1997 VCE359DJDARA * VCE661EJDARB M11 VCE661EJDARC M11 VCE661EJDASA M11 VCE661EJDATW M11 VCE855EJDARA N14 VCE855EJDARB N14 VCE855EJDARC N14 VCE855EJDATW N14 1998 WCEXA0359BAH ISB WCEXH0359BAD ISB WCEXH0359BAE ISB WCEXH0505CAC ISC WCEXH0505CAD ISC WCEXH0505CAE ISC WCEXH0505CAF ISC WCEXH0661MAA M11 WCEXH0661MAB M11 WCEXH0661MAD ISM WCEXH0661MAE ISM WCEXH0855NAA N14 WCEXH0855NAB N14 WCEXH0855NAC N14 WCEXH0912XAA Signature 1999 XCEXH0359BAJ ISB XCEXH0359BAK ISB XCEXA0359BAN ISB XCEXA0359BAT ISB XCEXH0505CAC ISC XCEXH0505CAD ISC XCEXH0505CAE ISC XCEXH0661MAH ISM XCEXH0661MAI ISM XCEXH0855NAD N14 XCEXH0855NAE N14 XCEXH0855NAF N14 XCEXH0912XAB Signature XCEXH0912XAD ISX 2000 YCEXH0359BAO ISB YCEXH0359BAP ISB YCEXH0359BAZ ISB YCEXA0505CAG ISC YCEXH0505CAH ISC YCEXH0505CAI ISC YCEXH0540LAA ISL YCEXH0661MAH ISM YCEXH0661MAI ISM YCEXH0855NAD N14 YCEXH0855NAE N14 YCEXH0855NAF N14 YCEXH0912XAC ISX YCEXH0912XAD ISX YCEXH0912XAE Signature, ISX 2001 1CEXA0359BAZ ISB 1CEXH0239BAD ISB 1CEXH0239BAE ISB 1CEXH0359BAU ISB 1CEXH0359BAV ISB 1CEXH0505CAN ISC 1CEXH0505CAO ISC 1CEXH0505CAP ISC 1CEXH0540LAA ISL 1CEXH0540LAC ISL 1CEXH0661MAQ ISM 1CEXH0661MAR ISM 1CEXH0855NAD N14 1CEXH0855NAE N14 1CEXH0855NAF N14 1CEXH0912XAC ISX 1CEXH0912XAD ISX 1CEXH0912XAE Signature, ISX 2002 2CEXA0359BAZ ISB 2CEXH0239BAD ISB 2CEXH0239BAE ISB 2CEXH0359BAB ISB 2CEXH0505CAN ISC 2CEXH0505CAQ ISC 2CEXH0540LAC ISL 2CEXH0661MAS ISM 2CEXH0855NAA N14 2CEXH0912XAF ISX

HINO Model Year Engine Family Series 1994 RHM3.8C7DARW * RHM6.5D7DARW * 1995 SHM6.5D7DARW * SHM3.8C7DARW * 1996 THM6.5D7DARW * THM3.8C7DARW * 1997 VHM8.0DHDARA *

DDC Model Year Engine Family Series 1994 RDD11.EJDARA Series 60 RDD12.EJDARA Series 60 RDD8.5EJDARA Series 50 RDD8.5EJDARW Series 50 1995 SDD11.EJDARA Series 60 SDD12.EJDARA Series 60 SDD8.5EJDARA Series 50 SDD8.5EJDARW Series 50 1996 TDD11.EJDARA Series 60 TDD12.EJDARA Series 60 TDD12.EJDATW Series 55 TDD8.5EJDARA Series 50 TDD8.5EJDARW Series 50 1997 VDD11.EJDARA Series 60 VDD12.EJDARA Series 60 VDD12.EJDATA Series 55 VDD8.5EJDARA Series 50 1998 WDDXH11.1EHD Series 60 WDDXH12.7EGD Series 60 WDDXH08.5EJD Series 50 1999 XDDXH11.1EHL Series 60 XDDXH12.7EGL Series 60 XDDXH14.0ELL Series 60 XDDXH08.5EJL Series 50 2000 YDDXH12.7EGL Series 60 YDDXH14.0ELL Series 60 YDDXH08.5EJB Series 50 YDDXH08.5EJL Series 50 2001 1DDXH12.7EGL Series 60 1DDXH14.0ELL Series 60 1DDXH08.5EJB Series 50 1DDXH08.5EJL Series 50 2002 2DDXH12.7EGL Series 60 2DDXH14.0ELL Series 60 2DDXH08.5EJL Series 50

GENERAL MOTORS Model Year Engine Family Series 1994 none * 1995 none * 1996 none * 1997 VGM6.5C6DARW * 1998 none 1999 XGMXH06.5523

VOLVO Model Year Engine Family Series 1994 RVT12.EJDBRA VE D12 RVT6.7D6DBRA VE D7A 1995 SVT12.EJDBRA VE D12 SVT6.7D6DBRA VE D7A 1996 TVT12.EJDBRA VE D12 TVT6.7D6DBRA VE D7A 1997 VVT12.EJDBRA VE D12 VVT6.7D6DBRA VE D7A 1998 WVTXH12.150S VE D12B WVTXH07.350S VE D7C 1999 XVTXH12.150S VE D12B XVTXH07.399B VE D7C XVTXH07.350S VE D7C 2000 YVTXH07.350S VE D7C YVTXH12.150S VE D12C 2001 1VTXH07.350S VE D7C 1VTXH12.150S VE D12 2002 2VTXH07.350S VE D7C 2VTXH12.150S VE D12

To reduce total emissions, existing engines (of the type described above) can be retrofitted with a diesel oxidation catalyst (DOC) muffler as described in FIGS. 9-14, along with a blow-by filter unit as described in FIGS. 2-8. A kit including both of these apparatus is provided in order to retrofit existing engines and enable the reduction of emissions by greater than 25%, and in some cases, up to 50%. These types of reductions in engines of the type above are achieved even though the systems do not make use of exhaust filter traps.

J. Other Exhaust Treatments

As discussed above, in connection with FIG. 15, the exhaust stream can be treated with a variety of treatments before being emitted through the tailpipe 45. In FIG. 15, this treatments is shown at 43′. The treatments can include (alone or in combination): diesel oxidation catalysts (as discussed above); flow through filters (with or without catalytic activity); diesel particulate filtration (active or passive, and with or without catalytic activity); NO_(x) treatment; and mufflers.

In general, a diesel particulate filter comprises a porous substrate that permits gases in the exhaust to pass through but traps the particulate material. Diesel particulate filters are efficient in reducing particulate matter emissions, achieving typical particulate matter reductions in excess of 90%. Typical diesel particulate filters include means to periodically regenerate the filter. By “regenerate the filter”, “regeneration”, and variants thereof, it is meant the burning off of the accumulated particulate material. The means to regenerate the filter is typically divided into two types of systems—passive and active. These two types of systems, passive and active, are discussed further below.

An example of a usable arrangement for diesel particulate filtration is shown in FIGS. 16 and 17. The arrangement in FIGS. 16 and 17 is a diesel particulate filter 800 having an inlet 802, an outlet 804, and a treatment body 806 therebetween. The treatment body 806 is embodied as a ceramic monolith 808. The monolith 808 can be made of cordierite, SiC, etc. The monolith 808 includes a plurality of parallel channels or flutes 810 extending between the inlet 802 and outlet 804. Each of the flutes 810 has an inlet end 811 adjacent to the inlet 802 and an outlet end 813 adjacent to the outlet 804. A first set of selected ones of the flutes 810 are open at the inlet end 811 and closed with plugs 812 at the outlet end 813; and a second set of selected ones of the flutes 810 are closed with plugs 814 at the inlet end 811 and open at the outlet end 813. As the exhaust enters the inlet 802, it flows into first set of flutes 810 (with the inlet ends 811 open). The exhaust cannot exit through the outlet end 813 of the first set of flutes 810 because the first set of flutes has the outlet ends 813 plugged. So, to exit, the exhaust gas (or aerosol) must flow through the porous walls of the monolith 808 to the second set of flutes to exit throught the outlet end 813. As the exhaust permeates through the walls, the soot particles are deposited within the wall pores as well as over the surface of the flutes 810.

The monolith 808 can be coated with an active catalyst, or the monolith 808 can be uncoated. If coated, the catalyst can facilitate diesel particulate matter oxidation by the oxygen present in the exhaust. Usable catalysts include: noble metals, base metals, and mixtures thereof. Platinum is useful, as well as palladium, rhodium, ruthenium, and mixtures thereof. Other useful material include: vavadium, magnesium, calcium, barium, copper, and silver.

Noble metal catalysts typically used in diesel filters contain platinum with promoters, such as alkaline earths. An example platinum catalyst developed by Engelhard is composed of 5-150 g/ft² Pt/Rh at 5:1 ratio and 30-1500 g/ft² of MgO. The catalyst is impregnated onto cordierite monoliths from water based solutions. A filter coated with the catalyst requires exhaust temperatures of 375°-400° C. to regenerate. The function of rhodium in the above formulation is to suppress the catalytic oxidation of SO₂ and, thus, the sulphate in the catalyst. The final effect depends on the Pt/Rh ratio.

Other examples of particulate exhaust filters are-described in commonly assigned and co-pending provisional patent application filed Nov. 4, 2003, entitled “Exhaust Filter”, invented by Steve Anderson et al., and carrying attorney docket number 758.1550USP1, which application is incorporated herein by reference.

As discussed above, diesel particulate filters can be either passive or active in terms of periodically regenerating the filter. A passive catalyzed diesel particulate filter reduces particulate material, carbon monoxide and hydrocarbon emissions through catalytic oxidation and filtration. In passive systems, the monolith 808 is coated with a catalyst material, typically a platinum group metal, or a separate catalyst is installed upstream of the particulate filter 800. The particulate filter 800 is positioned in the exhaust stream to trap or collect a significant fraction of the particulate emissions while allowing the exhaust gases to pass through the system. In passive diesel particulate filters, regeneration is accomplished by using a catalyst to lower the particulate matter ignition temperature because no outside source of energy is required for regeneration. Typical passive diesel particulate filters have reductions in excess of 90% for particulate material, along with similar reductions in carbon monoxide and hydrocarbons.

An active diesel particulate filter uses an external source of heat to oxidize the particulate material. Typical methods of generating additional heat for oxidation involve electrical regeneration by passing a current through the filter medium, injecting fuel to provide additional heat for particle oxidation, or adding a fuel-borne catalyst or other reagent to initiate regeneration. Some active diesel particulate filters induce regeneration automatically when a specified back pressure is reached. Others use an indicator, such as a warning light, to alert the operate that regeneration is needed, and require the operator to initiate the regeneration process.

As mentioned above, exhaust treatment 43′ can also include the use of flow through filters, with or without catalytic activity. Unlike diesel particulate filter 800, in which only gases can pass through the substrate, a flow through filter does not physically trap and accumulate particulate material. Instead, exhaust flows through a medium, such as a wire mesh, that has a high density of tortuous flow channels, thus giving rise to turbulent flow conditions. The flow through filter can be with or without catalytic activity. When it does have catalytic activity, the flow through filter is typically treated with an oxidizing catalyst that is able to reduce emissions of particulate matter, hydrocarbons, and carbon monoxide, or used in conjunction with a fuel-borne catalyst. Any particles that are not oxidized within the flow through filter flow out with the rest of the exhaust and do not accumulate. It should be appreciate that the filtration efficiency of a flow through filter is lower than that of a diesel particulate filter. A flow through filter is less likely to plug under unfavorable conditions than a diesel particulate filter. Unfavorable conditions can include high particulate matter emissions and low exhaust temperatures. The flow through filter, therefore, is useful in conditions that are not suitable for diesel particulate filters.

Diesel oxidation catalysts, discussed above, typically have straight flow passages and laminar flow conditions. As compared to diesel oxidation catalysts, a flow through filter achieves a greater particulate matter reduction because of more contact of particulate material with catalytic surfaces and longer residence times.

Examples of flow through filters include stainless wire mesh, ceramic foams, and louvered stainless foil.

As mentioned above, exhaust treatment 43′ can include diesel oxidation catalysts, flow through filters, diesel particulate filters, and combinations of these treatments. In addition, in combination with these treatments, there can be provisions to treat NO_(x). NO_(x) includes, for example, various oxides of nitrogen, in the form of, for example, smog. NO_(x) treatments include NO_(x) adsorbers, lean NO_(x) catalysts, selective catalytic reduction (scr), etc.

The exhaust treatment arrangement 43′ can include, in addition, fuel additives. Additives can reduce the total mass of particulate material, with variable effects on carbon monoxide, NO_(x), and gaseous hydrocarbon production. An additive added to diesel fuel in order to aid in soot removal by decreasing the ignition temperature of the exhaust is often called a fuel-borne catalyst. Fuel-borne catalysts can be used in conjunction with both passive and active filter systems to improve fuel economy, aid system performance, and decrease mass particulate matter emissions. Some additives include cerium based additives, platinum based additives, and iron based additives.

The exhaust treatment arrangement 43′ can also make use of alternative diesel fuels. Alternative diesel fuels include emulsified fuels, biodiesel fuels, Fischer Tropsch fuels, and combinations of these fuels with regular diesel fuel.

One example of alternative diesel fuel is an emulsion of diesel fuel and water. The process mixes water with diesel and adds an agent to keep the fuel and water from separating. The water is suspended in droplets with the fuel, creating a cooling effect on the fuel that decreases NO_(x) emissions.

The use of exhaust treatment 43′ in combination with a filter to treat crankcase emissions (as described above), can reduce total engine emissions. Data demonstrating the reduction of total engine emissions when using diesel oxidation catalysts is shown above in Section H. The following data are within the range of what is expected to be achieved, when using: (i) a flow through filter to treat engine exhaust; and (ii) a diesel particulate filter to treat the engine exhaust. These experiments were not actually run, but are the types of results that are expected to be achieved based on the principles described herein when the experiments are conducted. As can be seen from the data, total engine emissions (defined by emissions from the crankcase added to emissions from the tailpipe) are expected to be reduced.

TABLE A (Use of Flow Through Filter) MY 2000 CAT 3126, 7.2 L, 300 HP Total PM Tailpipe TP + PM Only % Reduction Crankcase Emissions Tailpipe Total PM % Test Fuel Used g/bhp-hr Baseline Baseline Reduction Avg. LSD 0.100 Baseline (350 ppm) 0.018 TP Avg. Baseline Crankcase Flow ULSD 0.050 50.0% 42.4% 57.6% Through (8 ppm) Filter and Spiracle ™ Crankcase Filter System

Estimated Emissions Performance

Notes:

-   -   Flow through filter at 50% tailpipe PM reduction     -   All % reduction to baseline fuel LSD (350 ppm)     -   Tailpipe only=0.05 g/bhp-hr reduced     -   Total PM=tailpipe+crankcase=0.68 g/bhp-hr reduced

These data demonstrate that when a flow through filter is used to treat engine exhaust at 43′, the total engine emissions are expected to be reduced by greater than 25%, indeed, greater than 50%.

TABLE B (Use of Diesel Particulate Filter) MY 2000 CAT 3126, 7.2 L, 300 HP Total PM Tailpipe TP + PM Only % Reduction Crankcase Emissions Tailpipe Total PM % Test Fuel Used g/bhp-hr Baseline Baseline Reduction Avg. LSD 0.100 Baseline (350 ppm) 0.018 TP Avg. Baseline Crankcase Diesel ULSD 0.015 85.0% 72.0% 87.3% Particulate (8 ppm) Filter (DPF) and Spiracle ™ Crankcase Filter System

Estimated Emissions Performance

Notes:

-   -   Diesel particulate filter at 85% tailpipe PM reduction     -   All % reduction to baseline fuel LSD (350 ppm)     -   Tailpipe only=0.085 g/bhp-hr reduced     -   Total PM=tailpipe+crankcase=0.103 g/bhp-hr reduced

These data demonstrate that when a diesel particulate filter is used to treat engine exhaust at 43′, the total engine emissions are expected to be reduced by greater than 25%, indeed, greater than 50%, and even greater than 85%.

The following data show actual, measured results of using a diesel particulate filter to treat exhaust, in combination with using a Donaldson Spiracle™ crankcase filter.

TABLE C (Use of Diesel Particulate Filter) MY 2000 CAT 3126, 7.2 L, 300 HP Total PM Tailpipe TP + PM Only % Reduction Crankcase Emissions Tailpipe Total PM % Test Fuel Used g/bhp-hr Baseline Baseline Reduction Avg. LSD 0.111 Baseline (8 ppm) 0.018 TP Avg. Baseline Crankcase Diesel ULSD 0.005 95.5% 82.2% 96.1% Particulate Filter (DPF) and (8 ppm) Spiracle ™ Crankcase Filter System

Measured Emission Performance

Notes:

-   -   Diesel Particulate Filter at 95.5% tailpipe PM reduction     -   All % reduction to baseline fuel LSD (8 ppm)     -   Tailpipe only=0.106 g/bhp-hr reduced     -   Total PM=tailpipe+crankcase=0.124 gmibhp-hr reduced

As can be seen from the data, the total engine emissions are reduced by greater than 90%, indeed greater than 95%.

Observations about Tables A, B, and C

California Air Resources Board (CARB) has a range of particulate matter (PM) Verification Levels for retrofits which now only refer to tailpipe PM reduction. These levels are defined as follows:

CARB PM Verification Levels

-   -   Level 1≧25%     -   Level 2≧50%     -   Level 3≧85%, or 0.01 g/bhp-hr

Table A provides estimated emission performance for the use of a Level 2 (50%+reduction) flow through filter (FTF) for tailpipe PM reduction and the use of a Spiracle crankcase filter system for crankcase PM reduction. “Spiracle” is a trademark of the assignee Donaldson company, and refers to, in this instance, the type of crankcase filter system described above in FIGS. 2-8.

Table B provides estimated emission performance for the use of a Level 3 (85%+reduction) diesel particulate filter (DPF) for tailpipe PM reduction and the use of a Spiracle crankcase filter system for crankcase PM reduction.

Table C provides measured emission performance for the use of a Level 3 (85%+reduction) DPF for tailpipe PM reduction and the use of a Spiracle™ crankcase filter system for crankcase PM reduction.

Table A shows the following estimated performance for 50% tailpipe PM control and crankcase PM control:

Adding crankcase PM control improves overall PM reduction from 42.4% to 57.6% as compared to a Total PM (tailpipe and crankcase) baseline.

This equates to a 36% improvement in overall gjbhp-hr PM reduction.

Table B shows the following estimated performance for 85% tailpipe PM control and crankcase PM control:

Adding crankcase PM control improves overall PM reduction from 72.0% to 87.3% as compared to a total PM (tailpipe and crankcase baseline).

This equates to a 21.2% improvement in overall g/bhp-hr PM reduction.

Table C shows the following measured emission performance for 99.5% tailpipe PM control and crankcase PM control.

Adding crankcase PM control improves overall PM reduction from 82.2% to 96.1% as compared to a total PM (tailpipe and crankcase) baseline.

This equates to a 17% improvement in overall g/bhp-hr PM reduction.

The above are examples. Many embodiments are contemplated. 

1. A method for retrofitting a diesel engine, the diesel engine drawing intake air through an air intake structure including an air filter for filtering the intake air, the method comprising: (a) installing a blow-by filter for filtering blow-by gas generated by the diesel engine to reduce blow-by gas emissions, the blow-by filter being installed in gas-flow communication with a blow-by vent structure of the diesel engine and in further gas-flow communication with the engine air intake structure; and (b) installing an exhaust treatment device for treating exhaust gas generated by the diesel engine to reduce exhaust gas emissions, the exhaust treatment device being installed in gas-flow communication with an engine exhaust port structure of the diesel engine, the exhaust treatment device including a substrate for reducing the exhaust gas emissions, the substrate being catalyzed with a diesel oxidation catalyst to promote the oxidation of hydrocarbons, wherein the blow-by filter and the exhaust treatment device are configured to provide at least a 25 percent reduction in total engine particulate matter emissions when the blow-by filter and the exhaust treatment device are used to retrofit a model year 1991-2003 on-highway diesel engine rated to produce from 150-600 horsepower.
 2. The method of claim 1, wherein the blow-by filter and the exhaust treatment device are installed on a model year 1991-2003 on-highway diesel engine rated to produce from 150-600 horsepower so as to retrofit the diesel engine in a manner that satisfies the minimum reductions in emissions required by government regulations governing retrofits of model year 1991-2003 on-highway diesel engines rated to produce from 150-600 horsepower.
 3. The method of claim 1, wherein the blow-by filter has a mass efficiency that exceeds 80 percent.
 4. The method of claim 1, wherein the blow-by filter has a mass efficiency that exceeds 90 percent.
 5. The method of claim 1, wherein the blow-by gas is directed to the air intake system at a location downstream of the air filter.
 6. The method of claim 1, wherein the substrate includes a ceramic substrate having a honeycomb like configuration of longitudinal channels.
 7. The method of claim 1, further comprising selling the blow-by filter and the exhaust treatment device as part of a retrofit kit.
 8. The method of claim 1, wherein the catalyzed substrate comprises a catalytic converter.
 9. The method of claim 1, wherein the catalyzed substrate comprises a flow through filter.
 10. The method of claim 1, wherein the catalyzed substrate comprises a diesel particulate filter.
 11. The method of claim 10, wherein the diesel particulate filter is a wall flow filter.
 12. The method of claim 11, wherein the wall flow filter includes a ceramic substrate having a honeycomb like configuration of longitudinal channels, with ends of the channels selectively plugged to encourage flow through walls of the longitudinal channels.
 13. A method for retrofitting a diesel engine, the diesel engine drawing intake air through an air intake structure including an air filter for filtering the intake air, the method comprising: using a blow-by filter for filtering blow-by gas generated by the diesel engine to reduce blow-by gas emissions, the blow-by filter being used in gas-flow communication with a blow-by vent structure of the diesel engine and in further gas-flow communication with the engine air intake structure; and using an exhaust treatment device for treating exhaust gas generated by the diesel engine to reduce exhaust gas emissions, the exhaust treatment device being used in gas- flow communication with an engine exhaust port structure of the diesel engine, the exhaust treatment device including a substrate for reducing the exhaust gas emissions, the substrate being catalyzed with a diesel oxidation catalyst to promote the oxidation of hydrocarbons, wherein the blow-by filter and the exhaust treatment device are configured to provide at least a 25 percent reduction in total engine particulate matter emissions when the blow-by filter and the exhaust treatment device are used to treat exhaust from a model year 1991-2003 on-highway diesel engine rated to produce from 150-600 horsepower.
 14. The method of claim 13, wherein the blow-by filter has a mass efficiency that exceeds 80 percent.
 15. The method of claim 13, wherein the blow-by gas is directed to the air intake system at a location downstream of the air filter.
 16. The method of claim 13, wherein the substrate includes a ceramic substrate having a honeycomb like configuration of longitudinal channels.
 17. The method of claim 13, further comprising selling the blow-by filter and the exhaust treatment device as part of a retrofit kit.
 18. The method of claim 13, wherein the catalyzed substrate comprises a catalytic converter.
 19. The method of claim 13, wherein the catalyzed substrate comprises a flow through filter.
 20. The method of claim 13, wherein the catalyzed substrate comprises a diesel particulate filter. 